This competing continuation to support of 5 post-doctoral positions for training in lung cellular and molecular biology. The purpose of the program is to provide Ph.D.s and M.D.s (primarily pulmonary physicians) with the specialized expertise required to become independent investigators in lung cellular and molecular biology. A secondary purpose is to provide a nidus of exciting lung-oriented research for attracting the best and the brightest young scientists into this field. The program is based in the Institute for Environmental Medicine while the interdisciplinary faculty is drawn from across the University of Pennsylvania Medical Center. The faculty have a long history of extensive interaction in research and training and routinely share resources and facilities for these purposes. The program is designed for 2-3 years of training for a broad range of candidates including those who have just received their advanced degree (Ph.D.) or specialty training (M.D.) up to more experienced candidates who desire to reorient their career towards lung-related research. The program provides the trainee with an intensive research experience with one or more preceptors, exposure to a broad range of technologies with direct relevance to investigation in lung cellular and molecular biology, experience in presentation of data to a critical audience, and development of skills in writing a manuscript for publication and a research grant for submission to a funding agency. The research activities emphasize "state of the art" techniques for the study of basic lung cellular and molecular biology using cell culture, biochemical analysis, molecular genetics, and morphologic imaging as primary disciplines. At the conclusion of the post-doctoral period, trainees will be prepared and expected to obtain an appointment at the junior faculty level in a Medical School or comparable position.